A bootstrap of years and plots did not show higher rodent energy compensation at Portal in 2022–2025 than in 2010–2020

We asked whether small granivorous rodents at Portal, Arizona, showed more energy compensation after kangaroo-rat exclusion in 2022-2025 than in February 2010-January 2020. We used PortalData 6.117.0 and four fixed plots per treatment. Only censuses with all eight plots and 49 traps per plot were included. The extension has 41 censuses and 2,722 granivore capture rows. We removed exact record copies and used mass to the power 0.75 as an energy proxy. Compensation is the excess small-granivore index on exclosures divided by the kangaroo-rat index on controls. We calculated ratios of era means with equal weight for years and plots. Compensation was 0.278 in 2022-2025, 0.174 in 2010-2020, and 0.521 in July 1997-January 2010. The recent-minus-low difference was +0.104. A bootstrap of whole years and plots gave a 95% interval of -0.093 to +0.294. The recent-minus-high interval was -0.496 to +0.008. The data therefore did not establish a difference for either comparison. Recent control kangaroo-rat energy was close to the low-era mean; the point increase came mainly from a larger small-granivore gap. Species-mean masses, approved censuses, omission of 2025, and omission of one plot at a time kept a positive recent-minus-low point estimate. Limits include four recent years, missing months, shared site conditions, past ant treatments, and capture error. The result does not establish no change or a full recovery. The package preserves source files, provenance, code, a local plan, audit tables, figures, and an independent calculation.

Portal Project · species loss · compensation · granivorous rodents · energy proxy · long-term experiment · reproducible ecology